Re-work the licenses annotations to use SPDX, instead of hard-coded values

[carlspring]

Task Description

Currently, we've hard-coded some more common licenses in the LicenseType enum class. We should replace this with the Java SPDX library and drop the need for this class, or make it work with SPDX.

Tasks

The following tasks will need to be carried out:

• Introduce the SPDX library to Strongbox.
• Investigate what will need to be done.
• Refactor the code.
• Add some tests.

Task Relationships

This task:

• Is a sub-task of: Make it possible to specify the license types of test artifacts #1723

Useful Links

• Java SPDX library

Help

• Our chat
• Points of contact:
  • @carlspring
  • @sbespalov
  • @steve-todorov